WETUMPKA IMPACT CRATER

 

THE BEST PRESERVED MARINE IMPACT CRATER IN THE WORLD 

The Big Bang

A prehistoric meteorite left a lasting impression on Central Alabama

In 1883 Alabamians had a front-row seat to one of the world’s most notable celestial events.  The meteor shower that paraded above the southern skyline virtually turned night into day  become known as “when stars fell on Alabama.”

But that pales in comparison with an event that occurred millions of years earlier.  That’s when a meteor the size of a large football stadium and weighing about 62 million tons smashed into the earth near Wetumpka.  The impact penetrated 2,000 feet into the ground and created a four-mile wide crater.

The collision carried the explosive energy of 2.3 billion tons of TNT and was 175,000 times more powerful than the nuclear bomb dropped on Hiroshima, says Dr. David King Jr., an Auburn University geologist who has spent years studying the site.

“When something that big hits the earth it causes quite a wallop,” King says.  “It was like a small mountain crashing  into earth.  It probably killed life by the hundred of thousands.”

Scientists estimate the event occurred between 80 and 85 million years ago.  It still has people talking.

Alabama was a different place when the earth served as a catcher’s mitt for this celestial hunk of rock and metal.  About half of the state, including the Wetumpka area, was part of the Gulf of Mexico and teemed with aquatic reptiles and sea life.  Fifteen to 20 miles to the northeast—beyond a line of sandy barrier islands—dinosaurs roamed shallow lagoons, swamplands and eventually firmer land that was lush with plant life including pine trees and magnolias. 

And while the late Cretaceous period is known as the last days of the dinosaurs, scientists say an abundance of food and a mild climate made it a good time to be alive for the Southeast dinosaur.  For the local living creatures, however, that was about to change.

King says the meteorite, which originated from a belt of meteors making their rounds in the solar system, smashed into the ocean and plunged into the earth’s crust, creating a huge explosion that formed the crater.

“It caused a bright infrared flash so powerful that it set the shoreline on fire,” says King.

The explosion was followed by an earthquake that would have registered 8.4 to 9.0 on the Richter scale.  The earthquake that struck San Francisco in 1906 destroying three-fourths of the city registered at most 8.3.

The Wetumpka impact also caused an atmospheric blast creating 175-mile-an-hour winds that likely extinguished the onshore fire.  By then, rock that had been blown into the air began showering the earth.

The destruction wasn’t finished.  The earthquake probably produced a 100-foot tsunami that caused destruction along coastlines throughout the region.

“It left a footprint of destruction on the earth,” King says.  “If it happened today, it would probably kill at least 400,000 people.”

Somewhere along in time a portion of the oval crater caved into the ocean giving it the horseshoe shape that today can be seen from space.

In 1891 the impact crater caught the eye of state geologist Eugene Allen Smith, but it wasn’t until earth samplings deep within the impact area were taken in 1998 that the area was officially declared an impact site.  Samples taken as far down as 685 feet revealed evidence of cooked minerals or “shocked” quartz.

“Shocked quartz is only found in impact craters and places where nuclear weapons have been tested,” King says.

The meteorite that basically wiped Wetumpka off the map has helped make it a popular place with scientists and others that have a fascination for geological wonders.

Scientists say it is the best preserved marine impact crater in the world.

Reprinted with permission from Alabama Living Magazine.